Piston MCP

What alvii147/piston-mcp MCP server does

alvii147/piston-mcp MCP server gives an MCP-connected LLM access to code execution through Piston. It is intended for clients that can start an MCP server as a local process, allowing the client to expose code-running functionality during a conversation.

The repository does not describe language-specific behavior, result formats, sandbox settings, or additional tools beyond its connection to Piston and code execution. Use it when the required workflow is for an agent to submit and execute code through a Piston deployment.

How it works

The client starts the server with uv tool run. The supplied configuration retrieves the package directly from the repository's main branch and invokes the piston_mcp command. After the process is registered in the MCP client's configuration, the client can communicate with the server and request code execution through Piston.

This arrangement keeps the server launcher local while the execution engine is Piston. It also does not document a custom endpoint setting or an environment-variable-based configuration.

Setup and configuration

Install uv first. The README provides installation commands for macOS, Linux, and Windows. Install an MCP client as well; Claude Desktop is the documented example.

Add a server entry similar to the following to the MCP client's configuration:

{
  "mcpServers": {
    "piston": {
      "command": "uv",
      "args": [
        "tool",
        "run",
        "--from",
        "git+https://github.com/alvii147/piston-mcp.git@main",
        "piston_mcp"
      ]
    }
  }
}

For Claude Desktop, the documented configuration paths are ~/Library/Application Support/Claude/claude_desktop_config.json on macOS and %APPDATA%\Claude\claude_desktop_config.json on Windows. Restart or reload the client as needed after saving the configuration.

Tools and capabilities

The alvii147/piston-mcp MCP server supports the core capability of executing code through Piston from an MCP client.

Limitations and notes

The repository warns that Piston's API is no longer publicly available as of February 15, 2026, and now requires an authorization token. Consequently, alvii147/piston-mcp will not work with the publicly hosted Piston instance unless the required authorization is available.

The example pins the source to the main branch rather than a release version. Review that choice if reproducible deployments are important. The project acknowledges Piston as its execution backend and Claude.ai as part of its usage context, but it does not document broader client-specific features.